/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "steadyParticleTracksTemplates.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

template<class Type>
bool Foam::fieldOk(const IOobjectList& cloudObjs, const word& name)
{
    IOobjectList objects(cloudObjs.lookupClass(IOField<Type>::typeName));

    return (objects.lookup(name) != nullptr);
}


template<class Type>
Foam::tmp<Foam::Field<Type>> Foam::readParticleField
(
    const word& name,
    const IOobjectList cloudObjs
)
{
    IOobjectList objects(cloudObjs.lookupClass(IOField<Type>::typeName));

    const IOobject* obj = objects.lookup(name);
    if (obj != nullptr)
    {
        IOField<Type> newField(*obj);
        return tmp<Field<Type>>(new Field<Type>(newField.xfer()));
    }

    FatalErrorInFunction
        << "error: cloud field name " << name << " not found"
        << abort(FatalError);

    return Field<Type>::null();
}


template<class Type>
void Foam::readFields
(
    PtrList<List<Type>>& values,
    const List<word>& fieldNames,
    const IOobjectList& cloudObjs
)
{
    IOobjectList objects(cloudObjs.lookupClass(IOField<Type>::typeName));

    forAll(fieldNames, j)
    {
        const IOobject* obj = objects.lookup(fieldNames[j]);
        if (obj != nullptr)
        {
            Info<< "        reading field " << fieldNames[j] << endl;
            IOField<Type> newField(*obj);
            values.set(j, new List<Type>(newField.xfer()));
        }
        else
        {
            FatalErrorInFunction
                << "Unable to read field " << fieldNames[j]
                << abort(FatalError);
        }
    }
}


template<class Type>
void Foam::writeVTK(OFstream& os, const Type& value)
{
    os  << value.component(0);
    for (label i=1; i<pTraits<Type>::nComponents; i++)
    {
        os  << ' ' << value.component(i);
    }
}


template<class Type>
void Foam::writeVTKFields
(
    OFstream& os,
    const PtrList<List<Type>>& values,
    const List<List<label>>& addr,
    const List<word>& fieldNames
)
{
    label step = max(floor(8/pTraits<Type>::nComponents), 1);

    forAll(values, fieldi)
    {
        Info<< "        writing field " << fieldNames[fieldi] << endl;
        os  << nl << fieldNames[fieldi] << ' ' << pTraits<Type>::nComponents
            << ' ' << values[fieldi].size() << " float" << nl;
        label offset = 0;
        forAll(addr, trackI)
        {
            const List<label> ids(addr[trackI]);

            List<Type> data(UIndirectList<Type>(values[fieldi], ids));
            label nData = data.size() - 1;
            forAll(data, i)
            {
                writeVTK<Type>(os, data[i]);
                if (((i + 1) % step == 0) || (i == nData))
                {
                    os  << nl;
                }
                else
                {
                    os  << ' ';
                }
            }
            offset += ids.size();
        }
    }
}


template<class Type>
void Foam::processFields
(
    OFstream& os,
    const List<List<label>>& addr,
    const List<word>& userFieldNames,
    const IOobjectList& cloudObjs
)
{
    IOobjectList objects(cloudObjs.lookupClass(IOField<Type>::typeName));

    if (objects.size())
    {
        DynamicList<word> fieldNames(objects.size());
        forAll(userFieldNames, i)
        {
            IOobject* obj = objects.lookup(userFieldNames[i]);
            if (obj != nullptr)
            {
                fieldNames.append(obj->name());
            }
        }
        fieldNames.shrink();

        PtrList<List<Type>> values(fieldNames.size());
        readFields<Type>(values, fieldNames, cloudObjs);

        writeVTKFields<Type>
        (
            os,
            values,
            addr,
            fieldNames
        );
    }
}


// ************************************************************************* //
